Which device runs directly from DC power?

Which device runs directly from DC power?

• A. DC traction motor
• B. Inverter
• C. AC traction motor
• D. Battery system

Answer: (A)

The main idea is that DC traction motors are designed to operate directly from the DC traction power supply. They connect straight to the DC bus and convert electrical energy to mechanical energy without needing any intermediate energy conversion. Speed and torque are controlled by adjusting the DC voltage/current, so no inverter or AC drive is required for the motor to run. Inverters, by contrast, take DC and convert it to AC to power AC machines or systems. An AC traction motor requires AC power to run, so it would not operate directly from DC without an inverter. A battery system is energy storage for DC energy and doesn’t itself drive a load unless it’s connected to a motor or converter; it’s not a device that runs on DC in the same sense as a motor does.

The main idea is that DC traction motors are designed to operate directly from the DC traction power supply. They connect straight to the DC bus and convert electrical energy to mechanical energy without needing any intermediate energy conversion. Speed and torque are controlled by adjusting the DC voltage/current, so no inverter or AC drive is required for the motor to run.

Inverters, by contrast, take DC and convert it to AC to power AC machines or systems. An AC traction motor requires AC power to run, so it would not operate directly from DC without an inverter. A battery system is energy storage for DC energy and doesn’t itself drive a load unless it’s connected to a motor or converter; it’s not a device that runs on DC in the same sense as a motor does.